Problem: If $x \barwedge y = 2x-5y$ and $x \oplus y = xy+3x-y$, find $2 \barwedge (1 \oplus -5)$.
Explanation: First, find $1 \oplus -5$ $ 1 \oplus -5 = -5+(3)(1)-(-5)$ $ \hphantom{1 \oplus -5} = 3$ Now, find $2 \barwedge 3$ $ 2 \barwedge 3 = (2)(2)-(5)(3)$ $ \hphantom{2 \barwedge 3} = -11$.